CVE-2025-50756
📋 TL;DR
This CVE describes a command injection vulnerability in Wavlink WN535K3 routers that allows attackers to execute arbitrary system commands by manipulating the newpass parameter in the set_sys_adm function. Attackers can gain complete control of affected devices, potentially compromising network security and connected systems. All users of Wavlink WN535K3 routers with firmware version 20191010 are affected.
💻 Affected Systems
- Wavlink WN535K3
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device takeover leading to persistent backdoor installation, network traffic interception, lateral movement to connected devices, and botnet recruitment.
Likely Case
Remote code execution allowing attackers to modify device configuration, steal credentials, or use the device as a pivot point for further attacks.
If Mitigated
Limited impact if device is behind strict firewall rules, not internet-facing, and network segmentation prevents lateral movement.
🎯 Exploit Status
Public GitHub repository contains proof-of-concept exploit code, making exploitation trivial for attackers with basic skills.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: Yes
Instructions:
1. Check Wavlink official website for firmware updates. 2. Download latest firmware for WN535K3. 3. Access router admin interface. 4. Navigate to firmware upgrade section. 5. Upload and apply new firmware. 6. Reboot router.
🔧 Temporary Workarounds
Network Isolation
allPlace router behind firewall and restrict access to admin interface
Access Control
linuxRestrict admin interface access to specific IP addresses only
iptables -A INPUT -p tcp --dport 80 -s TRUSTED_IP -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
🧯 If You Can't Patch
- Replace vulnerable device with supported hardware
- Implement strict network segmentation to isolate router from critical systems
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface under System Status or About pageCheck Version:
curl -s http://router-ip/cgi-bin/status.cgi | grep firmwareVerify Fix Applied:
Verify firmware version has been updated to a version later than 20191010📡 Detection & Monitoring
Log Indicators:
- Unusual command execution in system logs
- Multiple failed login attempts followed by successful admin access
- Suspicious processes running on router
Network Indicators:
- Unexpected outbound connections from router
- Port scanning originating from router IP
- DNS queries to known malicious domains
SIEM Query:
source="router.log" AND ("set_sys_adm" OR "newpass" OR "command injection")